Distributor drive arrangement for a rotary combustion

ABSTRACT

The inboard end of a distributor drive shaft is rotatably supported in a bearing in the stationary phasing gear of a rotary combustion engine to provide accurate positioning of the distributor&#39;&#39;s driven gear in relation to the distributor&#39;&#39;s driving gear which is mounted on the engine&#39;&#39;s crankshaft which is also rotatably supported in a bearing in the stationary phasing gear.

United States Patent Koivunen 1 June 24, 1975 [54] DISTRIBUTOR DRIVE ARRANGEMENT 3,163,156 12/1964 Peras .4 123/801 FOR A ROTARY COMBUSTION 3,764,234 10/1973 Morgan 123/801 X 3,794,010 2/1974 Palma 123/8.01 x [75] Inventor: Erkki A. Koivunen, Livoma, Mich.

{73] Assignee: General Motors Corporation, Primary Examiner-Clarence R. Gordon Detroit, Mich. Attorney, Agent, or Firm-Ronald L. Phillips [22] Filed: Apr. 25, 1974 211 Appl. No.: 463,913 [57] ABSTRACT The inboard end of a distributor drive shaft is rotat- 52 us. (:1 123/8.45; 123/801 ably suP11011611 a bearing in the stationary Phasing 51 Int. Cl. F0211 53/12;1=021 53/14 gear 3 combustim engine Provide accu- [58] Field of Search Q3/1345 8.0 805 rate positioning of the distributors driven gear in relation to the distributors driving gear which is mounted 56] References Cited on the engine s crankshaft which is also rotatably sup- UNITED STATES PATENTS ported in a bearing in the stationary phasing gear.

1,735,477 11/1929 Stuart 123/845 X 2 Claims, 4 Drawing Figures J? r in 1/ F f a? .7 2; i if if 1 E I I a 6'! L I I 1 l I! 1 147 iii L J DISTRIBUTOR DRIVE ARRANGEMENT FOR A ROTARY COMBUSTION This invention relates to a distributor drive arrangement for a rotary combustion engine and more particularly to such an arrangement that provides drive to the distributor from the engine crankshaft with very accurately related driving and driven gears to minimize gear backlash and consequently ignition spark scatter.

In rotary combustion engines, there is no camshaft from which a short drive can be provided to the distributor as in a reciprocating piston engine and as a result the distributor shaft may have to be very long to reach to the crankshaft to obtain the necessary drive. Because of this long reach and other factors such as space limitations, the typical distributor wherein the distributor shaft is wholly rotatably supported in the distributor body may not be suitable for use in a rotary engine in accomplishing the accurate relationship required between the axes of the distributors driving and driven gears to minimize gear backlash and consequently ignition spark scatter. On the other hand, it is known in reciprocating piston engines to journal the inboard end of the distributor shaft directly in a part of the engine housing such as the engine block or cylinder head adjacent the camshaft and as a result be able to provide accurate relationship between the axes of the driving and driven gears. However, in applying such an arrangement to the rotary engine of the present commercial type it has been found that because of the typically different type of mounting of the crankshaft as compared with a reciprocating piston engine it is very difiicult from a manufacturing standpoint to accurately maintain the desired relationship of the axes of the driving and driven gears when the distributor shaft is directiy supported at its inboard end in the engine housing.

In the distributor drive arrangement according to the present invention, accurate relationship between the axes of the driving and driven gears is provided in a rotary engine whose crankshaft is typically positioned by journal bearings mounted in stationary phasing gears which are secured to the housing of the engine rather than by bearings which are mounted directly in the engine housing. The distributor body is mounted externally on the engine housing and has a distributor shaft which is journaled at one end in the distributor body and extends to one of the stationary phasing gears in a direction transverse of the engine crankshaft. The distributor driving gear is mounted on the engine crankshaft adjacent this one stationary gear and meshes with the distributor driven gear which is secured to the dis tributor shaft near the inboard end thereof. The inboard end of the distributor shaft is supported by a bearing in this one stationary phasing gear and since this stationary phasing gear also supports the crankshaft and thus the driving gear, there is provided very accurate positioning of the driven gear in relation to the driving gear to minimize gear backlash and consequently ignition spark scatter.

An object of the present invention is to provide a new and improved distributor drive arrangement for a rotary combustion engine.

Another object is to provide in a rotary combustion engine having a crankshaft which is positioned by a journal bearing in a stationary phasing gear mounted in the housing of the engine a driving gear which is mounted on the engine crankshaft and a distributor shaft having a driven gear which meshes with the driving gear and is supported in a bearing also mounted in the stationary phasing gear.

Another object is to provide a distributor drive arrangement for a rotary combustion engine having a distributor shaft that is rotatably supported at one end in a stationary gear, which also rotatably supports one end of the crankshaft on which the distributor driving gear is mounted, to provide for very accurate relationship between the axes of the driven gear and the driving gear to minimize gear backlash and consequently ignition spark scatter.

These and other objects of the present invention will be more apparent from the following description and drawing in which:

FIG. I is a partial rear elevational view of a rotary combustion engine having a distributor drive arrangement according to the present invention.

FIG. 2 is a view taken along the line 2-2 in FIG. 1.

FIG. 3 is an enlarged fragmentary view taken along the line 33 in FIG. 2.

FIG. 4 is an enlarged cut-away view from FIG. 2.

Referring now to the drawings, the distributor drive arrangement according to the present invention is shown in a two-rotor rotary combustion engine which as seen in FIGS. 1 and 2 has a stationary housing consisting ofa front end housing 10, a rear end housing 12, an intermediate housing 14, a front rotor housing 16 between the front end housing 10 and intermediate housing 14 and a rear rotor housing 18 between the latter housing and the rear end housing 12, these housing parts being secured by long bolts, not shown, which extend therethrough. Typically, each of the rotor housings such as the rear rotor housing 18 has a two-lobed inner peripheral wall 20 that cooperates with oppositely facing housing side walls 22 and 24 to provide a cavity in which a three-lobed rotor 26 is located as shown in FIG. 2. A crankshaft 28 extends through the housing parts and has a pair of eccentrics 30, only one of which is shown, I apart on which the respective rotors in the front and rear rotor housings are rotatably mounted. The crankshaft 28 is rotatably supported near its two ends in the engine housing in a sleeve bearing 32 which is securely mounted in a hole 33 in a stationary phasing gear 34 that is secured by bolts 36 to the respective end housing, only the rear stationary phasing gear being shown as being necessary to understanding the invention. The rotors 26 are provided with suitable gas seals, parts of which are shown in FIG. 2, and cooperate with the respective peripheral wall 20 and side walls 22 and 24 to define three variable volume working chambers that are spaced about the rotor and move therewith within the engine housing.

A fixed cyclic relation between each of the rotors and the crankshaft is obtained by gearing between each of the rotors and the housing. This is shown in FIGS. 2 and 4 wherein for the rear rotor the stationary phasing gear 34 has external teeth 38 which are formed on the inboard end thereof concentric with the journal bearing 32 which positions the crankshaft 28. The external teeth 38 mesh with an internally toothed rotary phasing gear 40 that is concentric with and formed on the outboard side of the rear rotor 26. The rotary phasing gear 40 has one and one-half times the number of teeth as the stationary phasing gear 38 with the result that the crankshaft is forced to make three complete revolutions for every one complete revolution of the rotor. Similar rotary and stationary phasing gears that mesh at a location diametrically opposite that of the gears for the rear rotor are provided for the front rotor. Thus, the working chambers revolve with the respective rotors as they revolve about their axis while also revolving about the crankshaft axis with each chamber twice un dergoing expansion and contraction during each rotor revolution and the chambers in the two rotor housing cavities phased 60 apart. Referring to FIG. 1, a carburetor 42 delivers a combustible air-fuel mixture to an inlet manifold 44 which directs the mixture through the engine housing through intake porting to the chambers by the rotors opening and closing the intake porting at the proper time. A pair of spark plugs, not shown, which are fired by a distributor 46 ignite the mixture and after completion of the power phase the gas is exhausted through exhaust porting to an exhaust manifold 48 by the rotors opening and closing the exhaust porting at the proper time.

The rotary combustion engine structure thus far described is conventional and requires that the distributor 46 be driven at a speed proportional to the crankshaft 28 to effect proper firing of the spark plugs. For a more detailed description of this engine structure, reference may be made to copending U.S. patent application Ser. No. 432,848, filed Jan. 14, 1974 now U.S. Pat. No. 3,855,987 and assigned to the assignee of this invention. In addition, the distributor 46 together with an oil separator 49 is secured to the engine housing as shown in FIGS. 1 and 2 by a clamp assembly 50 of the type disclosed in copending U.S. patent application Ser. No. 361,874, filed May 21, 1973 now U.S. Pat. No. 3,851,849 and assigned to the assignee of this invention and to which reference may be made for further details thereof.

The distributor drive arrangement according to the present invention is particularly suited for the rotary engine structure described above wherein the body of the distributor 46 has a piloting cylindrical neck 52 which is received in an accommodating bore 54 in the rear end housing 12 as best shown in FIG. 2, there being provided an O-ring 56 in the neck to prevent oil for proceeding outward. The distributor 46 has a long distributor shaft 58 that is rotatably supported near its upper end within the distributor body and extends downwardly through the neck 52 into the interior of the rear end housing 12 and in a direction perpendicular to the axis of the crankshaft 28. But rather than supporting this long distributor shaft 58 in the engine housing according to conventional practice, this shaft according to the present invention is instead rotatably supported at its opposite or inboard end in a sleeve bearing 59 that is press-fitted in a hole 60 formed in a boss 61 provided on the outboard side of stationary gear 34 as best shown in FIG. 3. A driven gear 62 is concentrically mounted on and is secured by a pin 63 to the distributor shaft adjacent the bearing 59 and meshes with a driving gear 64 which is concentrically mounted on the crankshaft near the rear end thereof and is prevented from rotating relative thereto by a key 66 as best shown in FIG. 4. The driving gear 64 is positioned between thrust washers 68 and 70 that bear against an outboard shoulder of the stationary gear 34 and the interior face of a rear cover 72, the cover being secured together with the stationary gear 34 to the rear and housing by the bolts 36. A snap ring 74 received in a groove on the crankshaft 28 engages the outboard side of the driving gear 64 in thus nx the axial position thereof.

Thus, the rear stationary phasing gear 3% rotatably supports and thus positions the crankshaft 28 and thereby the distributor driving gear 64 and also the distributor drive shaft 58 and thereby the distributor driven gear 62. As a result, the desired relationship of the axes of the distributor driving and driven gears can be very accurately determined since manufacturing processes such as the forming of the accommodating holes 33 and for the respective crankshaft and distributor shaft bearings 32 and 59 and the finish forming of the internal diameter of these bearings after their installation can now be done on a common part, i.e., the rear stationary phasing gear. Furthermore, this simplifies the manufacturing operations and make it readily possible in mass production to maintain very accurate relationship between the axes of the driving and driven gears to minimize their backlash and consequently ignition spark scatter.

It will, of course, be appreciated that the distributor could be mounted on the front of this engine. In that case the distributor driving gear would be mounted near the front of the engine crankshaft and the bearing support for the driven gear of the distributor drive would then be provided in the front stationary phasing gear which also provides bearing support for the crankshaft.

The above embodiments are illustrative of the invention which may be modified within the scope of the appended claims.

I claim:

I. A rotary combustion engine comprising housing means having internal walls cooperatively defining a cavity, a crankshaft having an eccentric located in said cavity, a pair of crankshaft journal bearing means rotatably supporting said crankshaft in said housing on opposite sides of said eccentric, a rotor rotatably mounted on said eccentric in said cavity, a rotary phasing gear concentric with said eccentric and fixed to one side of said rotor, one of said crankshaft journal bearing means comprising a stationary phasing gear fixed to said housing means and meshing with said rotary phasing gear, said rotor cooperating with said walls of said housing to provide a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor and said crankshaft rotate, intake passage means for supplying said working chambers with a combustible mixture, a spark plug for igniting the mixture in said working chambers, exhaust passage means for exhausting said working chambers, a distributor for operating said spark plug comprising a stationary body secured to said housing means, a distributor shaft rotatably supported in said distributor body and extending within said housing means to said stationary gear, a dis tributor driving gear concentric with and fixed to said crankshaft adjacent said stationary gear, a distributor driven gear concentric with and fixed to said distributor shaft, and means for rotatably supporting said distributor shaft in said stationary gear whereby said stationary gear provides a bearing support for both said distri butor driving gear and said distributor driven gear to assure accurate relationship between their axes to minimize gear backlash and consequently ignition spark scatter.

2. A rotary combustion engine comprising housing means having internal walls cooperatively defining a cavity, a crankshaft having an eccentric located in said cavity, a pair of crankshaft journal bearing means rotatably supporting said crankshaft in said housing on opposite sides of said eccentric, a rotor rotatably mounted on said eccentric in said cavity. a rotary phasing gear concentric with said eccentric and fixed to one side of said rotor, one of said crankshaft journal bearing means comprising a stationary phasing gear fixed to said housing means and meshing with said rotary phasing gear, a journal bearing mounted in said stationary gear rotatably supporting and positioning said crankshaft, said rotor cooperating with said walls of said housing to provide a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor and said crankshaft rotate, intake passage means for supplying said working chambers with a combustible mixture, a spark plug for igniting the mixture in said working chambers, exhaust passage means for exhausting said working chambers, a distributor for operating said spark plug comprising a stationary body secured to said housing means, a distributor shaft rotatably supported near one end in said distributor body and extending within said housing means to said stationary gear at right angles to said crankshaft, a distributor driving gear concentric with an fixed to said crankshaft adjacent said stationary gear, a distributor driven gear concentric with and fixed to said distributor shaft near the other end thereof, and a bearing mounted in said stationary gear at right angles to said journal bearing and receiving said other end of said distributor shaft whereby said stationary gear provides a bearing support for both said distributor driving gear and said distributor driven gear to assure accurate relationship between their axes to minimize gear backlash and consequently ignition spark scatter.

III =0 I! 

1. A rotary combustion engine comprising housing means having internal walls cooperatively defining a cavity, a crankshaft having an eccentric located in said cavity, a pair of crankshaft journal bearing means rotatably supporting said crankshaft in said housing on opposite sides of said eccentric, a rotor rotatably mounted on said eccentric in said cavity, a rotary phasing gear concentric with said eccentric and fixed to one side of said rotor, one of said crankshaft journal bearing means comprising a stationary phasing gear fixed to said housing means and meshing with said rotary phasing gear, said rotor cooperating with said walls of said housing to provide a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor and said crankshaft rotate, intake passage means for supplying said working chambers with a combustible mixture, a spark plug for igniting the mixture in said working chambers, exhaust passage means for exhausting said working chambers, a distributor for operating said spark plug comprising a stationary body secured to said housing means, a distributor shaft rotatably supported in said distributor body and extending within said housing means to said stationary gear, a distributor driving gear concentric with and fixed to said crankshaft adjacent said stationary gear, a distributor driven gear concentric with and fixed to said distributor shaft, and means for rotatably supporting said distributor shaft in said stationary gear whereby said stationary gear provides a bearing support for both said distributor driving gear and said distributor driven gear to assure accurate relationship between their axes to minimize gear backlash and consequently ignition spark scatter.
 2. A rotary combustion engine comprising housing means having internal walls cooperatively defining a cavity, a crankshaft having an eccentric located in said cavity, a pair of crankshaft journal bearing means rotatably supporting said crankshaft in said housing on opposite sides of said eccentric, a rotor rotatably mounted on said eccentric in said cavity, a rotary phasing gear concentric with said eccentric and fixed to one side of said rotor, one of said crankshaft journal bearing means comprising a stationary phasing gear fixed to said housing means and meshing with said rotary phasing gear, a journal bearing mounted in said stationary gear rotatably supporting and positioning said crankshaft, said rotor cooperating with said walls of said housing to provide a plurality of chambers that are spaced about and move with said rotor while varying in volume as said rotor and said crankshaft rotate, intake passage means for supplying said working chambers with a combustible mixture, a spark plug for igniting the mixture in said working chambers, exhaust passage means for exhausting said working chambers, a distributor for operating said spark plug comprising a stationary body secured to said housing means, a distributor shaft rotatably supported near one end in said distributor body and extendiNg within said housing means to said stationary gear at right angles to said crankshaft, a distributor driving gear concentric with an fixed to said crankshaft adjacent said stationary gear, a distributor driven gear concentric with and fixed to said distributor shaft near the other end thereof, and a bearing mounted in said stationary gear at right angles to said journal bearing and receiving said other end of said distributor shaft whereby said stationary gear provides a bearing support for both said distributor driving gear and said distributor driven gear to assure accurate relationship between their axes to minimize gear backlash and consequently ignition spark scatter. 